Circular No. 8686
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
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Phone 617-495-7440/7244/7444 (for emergency use only)


S/2005 P 1 AND S/2005 P 2
     S. A. Stern, Southwest Research Institute (SwRI); H. A.
Weaver, Applied Physics Laboratory, Johns Hopkins University; M. J.
Mutchler, Space Telescope Science Institute; A. J. Steffl, W. J.
Merline, and J. R. Spencer, SwRI; M. W. Buie, Lowell Observatory;
and E. F. Young and L. A. Young, SwRI, report color observations of
the newly discovered small satellites of Pluto (cf. IAUC 8625, 8676)
using the Hubble Space Telescope (+ ACS/HRC) on Mar. 2.75 UT.
During these observations, S/2005 P 1 was at an average position of
2".69 from the photo-center of Pluto at p.a. 138 deg, and S/2005 P
2 was 1".43 away at p.a. 214 deg.  Using ACS filters F606W and
F435W, and adopting for Pluto I (Charon) the value B-V = +0.710
(Buie et al. 1997, Icarus 125, 233), B-V colors +0.653 +/- 0.026
and +0.654 +/- 0.065 were found for S/2005 P 1 and S/2005 P 2,
respectively.  These colors indicate that the observed hemispheres
of all three of Pluto's satellites are essentially neutral, with
only minor differences among them, as might be expected for bodies
having a similar origin and sharing a similar environment.  Given
that a much redder color of B-V = +0.91 +/- 0.15 was reported for
S/2005 P 2 (Buie et al. 2006,
http://xxx.lanl.gov/abs/astro-ph/?0512491), additional
observations are solicited.


SUPERNOVAE 2006aq, 2006ar, AND 2006as
     CBET 423 contains details of a type-Ia supernova (mag
approximately 19.9, calibrated to R) discovered by the "Nearby
Supernova Factory" collaboration on NEAT images taken on Feb. 24.5
UT:  SN 2006as is located at R.A. = 13h51m24s.88, Decl. =
-11o15'26".8 (equinox 2000.0).  They also obtained spectra (range
320-1000 nm) of supernovae 2006aq and 2006ar (cf. IAUC 8684) on
Mar. 7.6 and 7.5 UT, respectively; 2006aq is a type-II event that
appears to have faded rapidly relative to the reported discovery
magnitude.  Type-Ia supernova 2006ar is before or near maximum.


COMET C/2006 A1 (POJMANSKI)
     Visual total-magnitude estimates:  Feb. 11.34 UT, 6.2 (L. A.
Mansilla, Rosario, Argentina, 7x50 binoculars); 27.32, 5.2 (W.
Souza, Mairipora, Brazil, naked eye); Mar. 3.83, 5.1 (K. Yoshimoto,
Yamaguchi, Japan, 7x35 binoc.); 8.21, 5.4 (J. J. Gonzalez, Leon,
Spain, 7x50 binoc.; 2.5-deg tail in p.a. 285 deg); 9.20, 5.8 (A.
Baransky, Pylypovychi, Ukraine, 10x50 binoculars).

                      (C) Copyright 2006 CBAT
2006 March 9                   (8686)            Daniel W. E. Green